1. Field of the Invention
The present invention relates to a substrate processing apparatus, a method of manufacturing a semiconductor device and a non-transitory computer-readable recording medium.
2. Description of the Related Art
In general, a substrate processing apparatus for performing processes (e.g., a film forming process) on a substrate (e.g., a wafer) is used in a process of manufacturing a semiconductor device. With the scaling-up of a substrate or an increase in the precision of processes, a single-wafer-type substrate processing apparatus configured to process substrates one by one has widely been used as the substrate processing apparatus.
As a process performed by the single-wafer-type substrate processing apparatus, there is, for example, a film forming process using an alternate supply method. An alternate supply process includes forming a film on a substrate in a processing space by repetitively performing a cycle including a source gas supply process, a purge process, a reactive gas supply process and a purge process a predetermined number of times (n cycles) on the substrate. Accordingly, to efficiently perform the alternate supply process, it is necessary to unite a process of uniformly supplying gases onto the substrate in the processing space with a process of rapidly exhausting the remnant gases from the processing space. Thus, some single-wafer-type substrate processing apparatuses are configured to supply a process gas into a processing space through an upper side via a shower head serving as a gas dispersion mechanism, and discharge gases from the center of a substrate toward an outer circumferential side (i.e., a side portion of the processing space) of the substrate via an exhaust buffer chamber which is installed to surround an outer circumference of the side portion of the processing space and has a downstream side connected to an exhaust pipe.
These substrate processing apparatuses need to periodically remove unnecessary films (reaction byproducts, etc.) adhered to the shower head or the processing space. Therefore, in some single-wafer-type substrate processing apparatuses, a cleaning process is performed on a processing space by supplying a cleaning gas into the processing space via a shower head (for example, refer to Patent document 1). In addition, in other substrate processing apparatuses, a cleaning gas is directly supplied into an exhaust pipe disposed at a downstream side of a processing space in a gas exhaust direction to perform a cleaning process on the exhaust pipe which is a point to which byproducts are easily adhered and from which removing the byproducts is difficult (for example, refer to Patent document 2).
1. Japanese Patent Laid-open No. 2005-109194
2. Japanese Patent Laid-open No. 2004-211168